He that saith he is in the light, and hateth his brother, is in darkness even until now.

he who is saying, in the light he is, and his brother is hating, in the darkness he is till now;

Any one who professes to be in the light and yet hates his brother man is still in darkness.

He who says that he is in the light, and has hate in his heart for his brother, is still in the dark.

Whoever declares himself to be in the light, and yet hates his brother, is in the darkness even now.

The person who says that they are in the light, and yet hates others, is still in the darkness.

He that saith he is in the light He pursues the same metaphor. He said that love is the only true rule according to which our life is to be formed; he said that this rule or law is presented to us in the Gospel; he said, lastly, that it is there as the meridian light, which ought to be continually looked on. Now, on the other hand, he concludes that all are blind and walk in darkness who are strangers to love. But that he mentioned before the love of God and now the love of the brethren, involves no more contrariety than there is between the effect and its cause. Besides, these are so connected together that they cannot be separated. John says in the third chapter, that we falsely boast of love to God, except we love our brethren; and this is most true. But he now takes love to the brethren as a testimony by which we prove that we love God. In short, since love so regards God, that in God it embraces men, there is nothing strange in this, that the Apostle, speaking of love, should refer at one time to God, at another to the brethren; and this is what is commonly done in Scripture. The whole perfection of life is often said to consist in the love of God; and again, Paul teaches us, that the whole law is fulfilled by him who loves his neighbor, (Romans 13:8;) and Christ declares that the main points of the law are righteousness, judgment, and truth. (Matthew 23:23.) Both these things are true and agree well together, for the love of God teaches us to love men, and we also in reality prove our love to God by loving men at his command. However this may be, it remains always certain that love is the rule of life. And this ought to be the more carefully noticed, because all choose rather almost anything else than this one commandment of God. To the same purpose is what follows, and there is no occasion of stumbling in him -- that is, in him who acts in love; for, he who thus lives will never stumble. [1]

Footnotes

1 - Literally, "and to him there is not a stumblingblock;" that is, nothing that causes him to stumble or fall. He is not like him mentioned in the next verse, who "walks in darkness and knows not whither he goeth." The sentence seems to have been taken from Psalm 119:165, with this only difference, that it is "to them," instead of "to him." There is in the Sept no preposition, but in Hebrew the preposition "to" is used; and en has sometimes this meaning in the New Testament. See Colossians 1:23; 1-Thessalonians 4:7. -- Ed.

He that saith he is in the light - That he has true religion, or is a Christian. See 1-John 1:7.
And hateth his brother - The word "brother" seems here to refer to those who professed the same religion. The word is indeed sometimes used in a larger sense, but the reference here appears to be to that which is properly brotherly love among Christians. Compare Lucke, in loc.
Is in darkness even until now - That is, he cannot have true religion unless he has love to the brethren. The command to love one another was one of the most solemn and earnest which Christ ever enjoined, John 15:17; he made it the special badge of discipleship, or that by which his followers were to be everywhere known, John 13:35; and it is, therefore, impossible to have any true religion without love to those who are sincerely and truly his followers. If a man has not that, he is in deep darkness, whatever else he may have, on the whole subject of religion. Compare the notes at 1-Thessalonians 4:9.

He that saith he is in the light - He that professes to be a convert to Christianity, even in the lowest degree; and hateth his brother - not only does not love him, but wills and does him evil, as the Jews did the Gentiles; is in darkness - has received no saving knowledge of the truth; and, whatever he may pretend, is in heathen ignorance, or even worse than heathen ignorance, to the present time, notwithstanding the clear shining of the light of the Gospel.

(8) He that saith he is in the light, and hateth his brother, is in darkness even until now.
(8) Now he comes to the second table, that is, to charity towards one another, and denies that a man has true light in him, or is indeed regenerate and the son of God, who hates his brother: and such a one wanders miserably in darkness, may he never brag of great knowledge of God for he knowingly and willingly casts himself headlong into hell.

He that saith he is in the light,.... Is in Christ the light, or has the true knowledge of the light of the Gospel, or is illuminated by the Spirit of God; for persons may profess to be enlightened ones, and not be so: wherefore the apostle does not say, he that is in the light, but he that says he is,
and hateth his brother; who is so either by creation, as all men are brethren, having one Father, that has made them, and brought them up; or by regeneration, being born of God the Father, and in the same family and household of faith; and so regards such who are in a spiritual relation, whom to hate internally, or not to love, is inconsistent with being in the light, or having faith, which is always naturally and necessarily accompanied with the heat of love; for as light and heat, so faith and love go together: wherefore, let a man's profession of light be what it will, if love to his brother is wanting, he
is in darkness even until now; he is in a state of nature and unregeneracy, which is a state of darkness and ignorance; he is under the power of darkness, and in the kingdom of Satan; who is the ruler of the darkness of this world; he ever was so from his birth; he never was called nor delivered out of it, but is still in it to this moment, and so remains. This seems to be very much levelled against the Jews, who make hatred of the brother in some cases lawful: for they say (d),
"if one man observes sin in another, and reproves him for it, and he does not receive his reproof, , "it is lawful to hate him";''
See Gill on Matthew 5:43.
(d) Moses Kotsensis Mitzvot Tora, pr. neg. 5.

There is no mean between light and darkness, love and hatred, life and death, God and the world: wherever spiritual life is, however weak, there darkness and death no longer reign, and love supplants hatred; and Luke 9:50 holds good: wherever life is not, there death, darkness, the flesh, the world, and hatred, however glossed over and hidden from man's observation, prevail; and Luke 11:23 holds good. "Where love is not, there hatred is; for the heart cannot remain a void" [BENGEL].
in the light--as his proper element.
his brother--his neighbor, and especially those of the Christian brotherhood. The very title "brother" is a reason why love should be exercised.
even until now--notwithstanding that "the true light already has begun to shine" (1-John 2:8).

He that saith he is in the light - In Christ, united to him. And hateth his brother - The very name shows the love due to him. Is in darkness until now - Void of Christ, and of all true light.